12. But in terms of high-profile guest appearances, arguably the biggest was Michael Jackson in 1991 episode “Stark Raving Dad”. There is some controversy about whether it’s actually him as he wouldn’t let them use his name in the credits, but it DEFINITELY was.

13. However, though it was his voice when he was talking, he wasn’t allowed to sing, so an impersonator was used to record “Happy Birthday Lisa”.

14. Jackson also had another link with the show – he co-wrote and produced Bart’s chart topping hit, “Do the Bartman”.

15. Sideshow Bob and Principal Skinner shared the prison number 24601 (the latter during Vietnam). This was also the prison number of Hank Jennings in Twin Peaks and Jean Valjean in Les Misérables.

16. As well as voicing characters such as Bart, Nelson, and Ralph, Nancy Cartwright also played Chuckie in Rugrats from 2002 to 2004.

17. After the tragic death of Phil Hartman in 1998, all of his characters were retired, including Lionel Hutz and fan-favourite Troy McClure. They do sometimes appear silently in crowd shots, however.

18. Maude Flanders was killed off after voice artist Maggie Roswell felt Fox wasn’t paying her enough and decided to leave the show. She has since returned, but sadly it was too late for poor old Maude.

19. According to the DVD commentary, “The City of New York vs Homer Simpson” wasn’t aired for five years after 9/11 because the episode focuses heavily on the World Trade Center.

27. The Simpson family were very nearly rabbits. Groening told the BBC: “I was going to do something completely different but then thought to myself, ‘I’ll do humans instead of bunny rabbits,’ which was my original idea. And then I just drew them really quickly.”

28. In the original opening titles the price that appears on the cash register when Maggie is scanned is $847.63. According to Matt Groening this was the monthly cost of raising a child in 1989.